The present invention relates to a pushbutton-operated waveband or station selector or tuner and more-particularly to improvements in the link mechanism.
In the pushbutton-operated waveband or station selector, as a selected pushbutton is depressed, the memory plate is moved and coupled with the core slide so that the pressure applied to the pushbutton is transmitted to the core slide on which a core is fitted, this core being thus inserted into or extracted out of the tuning coil, or as the manual tuning knob is turned, it causes the core slide to move so as to change the inserted position of the core inside the tuning coil. In many of such conventional techniques, the core slide on which the coil is secured moves in a direction different from that in which the memory plate moves to shift the core slide or the tuning shaft-side shifting member. For example, the memory plate and the tuning knob-side shifting member are so disposed as to be movable in the direction of the pushbutton width, while the core slide is so disposed as to be movable in the direction perpendicular (front-rear direction of the pushbutton) to the moving direction of the memory plate and tuning knob-side shifting member. Therefore, in order to operatively couple these members, there is provided between them a link which provides for an operative coupling of them and changes the moving directions of them.
In the conventional pushbutton-operated waveband or station selector, two members for shifting toward different directions from each other are operatively connected by means of an L shape link with two arms. However, a pushbutton-operated waveband selector generally has many operatively coupled members like a memory plate, core slide, tuning knob-side shifting members, kick arm, etc. Therefore, such a conventional link mechanism which links only two members is not suitable for simultaneously coupling such a large number of members. Particularly, when operatively connecting three or more members in the conventional link mechanism, a link is used for the first and second members and another link is further provided for connecting the third member to the first and second members, which means increase of the number of links and accordingly increase of parts of the entire pushbutton-operated waveband selector. This results in difficulty of thinning the waveband selector. Increase of links also means increase of connecting portions between members to cause the loss of power transmission and looseness at the connecting portions. These phenomena give bad influences to the shifting position of the core inside the tuning coil to cause a frequency deviation.